Isospecific polymerization of alpha-olefins in the presence of metallocomplex catalysts fixed on graphite

Studies of activity and stereospecificity in polymerizations of propylene and butene-l with several metal-complex catalysts fixed on a graphite surface are reported. High catalytic activity was observed at a strictly determined Ti:graphite ratio. Maximum stereospecificity is observed at the maximum of catalytic activity. Characterization of the catalyst obtained from the interaction of TiCl4-(C2H5)(2)AlCl with graphite by chromatographic, polarographic, X-ray and ESR techMques was directed to the origin of the modifying effect of graphite. These results indicated the formation of stable metal complexes containing Ti compounds with Ti-C2H5 moieties in the sites of crystal-lattice defects. Some electrophysical and mechanical properties of polypropylene-graphite sample are also presented. Copyright (C) 1996 Elsevier Science Ltd